Our goal remains the same as put forth in our original proposal, i.e., to capitalize on the infrastructure and strengths of the existing national quality assurance (QA) programs, including the Image-Guided Therapy Center (ITC) (previously referred to as the 3DQA Center in the original grant), Quality Assurance Review Center (QARC), Radiological Physics Center (RPC), and the, Radiation Therapy Oncology Group(RTOG) to create an Advanced Technology Radiation Therapy Clinical Trials Support (ATC) QA consortium. Our ATC QA consortium approach will avoid duplication of these already defined programs, while strengthening interactions between QA groups which promote the development of common QA for advanced technology clinical trials throughout all participating Cooperative Groups. Specifically, we will (1) provide and/or facilitate QA review of RTOG clinical trials that utilize advanced technologies including, but not limited to, three-dimensional radiation therapy treatment planning and delivery(3DCRT), intensity modulated radiation therapy (IMRT), stereotactic radiosurgery/radiation therapy, and brachytherapy;(2)assist(facilitate receipt of digital data) QARC in their QA review of cooperative group clinical trials that utilize advanced technologies;(3) assist (facilitate receipt of digital data) RPC in their QA review of cooperative group clinical trials that utilize advanced technologies; (4) develop Monte Carlo simulation capability (through a subcontract with Fox Chase Cancer Center) for the purpose of credentialing and QA pertaining to clinical trials utilizing advanced technologies;(5) develop QA and credentialing criteria that is compatible with the level of complexity of the clinical trial treatment regimens;(6) create mechanisms and software tools to facilitate QA reviews of treatment planning and verification(TPV) data submitted by institutions participating in cooperative group clinical trials (both pediatric and adult) that utilize advanced technologies. Emphasis will be on the development and improvement of web-based remote-review tools that allow for the efficient review of centrally-located image-based data by reviewers not co-located with the data; (7) develop efficient methodologies for electronic data exchange of TPV data between the ITC and the participating institutions, remotely located QA review group(s), and Cooperative Group?s Operations, Statistics, and Data Management Group(s); (8) develop and maintain an archival TPV database that can be linked with the Cooperative Group?s clinical outcomes database; (9) construct normal tissue complication probability(NTCP) models to demonstrate use of TPV database, and (10) serve as a resource to the nation?s Cooperative Groups and participating institutions for support of advanced technology radiation therapy dinical trials.